I tried a swamp cooler in my RV when 1 of the A/C units failed and the results were quite obvious. If you stood right in front of the air outlet it felt pretty good. However, it did absolutely nothing to actually cool the interior of the RV. We then bought a "real" portable A/C unit with an exhaust hose that must be run out the window. THAT WORKS! However, it generates a whole lot of water which you must deal with on a frequent basis or have an option allowing a continuous drain of the water condensation. Luckily, we were able to run a hose from the A/C unit to a drain and it could run 24 hours without attention. If not, the water needed to be drained every couple of hours to prevent over-flow.